PS25203B Plessey

PS25203 EPIC sensor, electrophysiology, low gain datasheet Fig. 1 PS25203B - Top and Bottom Plessey Semiconductors Electric Potential Integrated Circuit (EPIC) product line targets a range of applications. The PS25203B is an ultra high impedance solid state ECG (electrocardiograph) sensor. It can be used as a dry contact ECG sensor without the need for potentially dangerous low impedance circuits across the heart. The resolution available is as good as or better than conventional wet electrodes. The device uses active feedback techniques to both lower the effective input capacitance of the sensing element (Cin) and boost the input resistance (Rin). These techniques are used to realise a sensor with a frequency response suitable for both diagnostic and monitoring ECG applications. FEATURES Ultra high input resistance, typically 20G. Dry-contact capacitive coupling. Input capacitance as low as 15pF. Lower -3dB point typically 200mHz. Upper -3dB point typically 20kHz. Operates with bipolar power supply from 2.4V to 4.0V. Sensors supplied in a custom package with exposed pins for surface mount assembly. Page 2 of 6 Document number 291839 V3 APPLICATIONS Contact ECG signal detection for: Non-critical patient monitoring equipment. Emergency response diagnostics. Lifestyle sports and health products. Suitable for long-term and remote monitoring. Fig. 2 Internal circuit of EPIC ECG Sensor ELECTRICAL CHARACTERISTICS T = -25C to +75C,Vdd/Vss 2.4V to 4.0V. The electrical characteristics are guaranteed amb by either production test or by design and characterisation. They apply within the specified ambient temperature and supply voltage unless otherwise stated. Value Characteristics Conditions Min. Typ. Max. Units Supply voltage 2.4 4.0 V Bipolar supply, Gnd=0V Supply current 1.5 2.5 3.5 mA Effective input resistance 20 G Effective input capacitance 15 pF Voltage Gain (Av) 10 Coupling capacitance 250 pF Sensor to skin Set by internal DC signal rejection Lower -3dB point 0.20 Hz network coupling capacitor 250pF Upper -3dB point 20.0 kHz Noise tbd